Why do you want your next patient's cataract surgery to be under topical anaesthesia?

Although I saw this patient some months ago, I remember his case vividly.

He was a successful executive in his late 50s, referred for a second opinion after undergoing combined cataract and vitrectomy surgery on his right eye. Before the operation, his vision was a reasonable 6/9. He was healthy and had no history of major surgeries. He had a thriving career and a loving family.

But everything changed after the operation.

When he came to my office, he was clearly distressed, though he tried to hide it. His right eye was the source of his anxiety. His best corrected visual acuity was now reduced to counting fingers.

The surgery itself, performed under subtenon anesthesia, was described as uneventful. He wore a patch overnight and seemed fine. But the next morning, when he removed the patch, he was met with a devastating surprise: he couldn't see out of his right eye.

His surgeon saw him immediately. The eye appeared normal on examination, and the retina looked healthy under the slit lamp. However, an OCT scan revealed widespread inner retinal ischemia – increased reflectivity and thickening. Further tests, including a fluorescein angiogram and a stroke work-up, did not show any other abnormalities. His surgeon was not able to give him a clear answer, which is why he found himself in my office, desperate for answers.

I immediately suspected the diagnosis, confirmed by a repeat OCT:

Day-one "patch-off" vision loss

I explained to him that this is a 1 in 1300 complication where there is retinal ischaemia after an intraocular operation. The OCT findings are distinctive. The damage is irreversible, but non-progressive, and doesn't indicate any increased risk of stroke or heart attack. I shared relevant research, including the Melbourne study and its accompanying editorial. He was grateful for the explanation and the certainty of a diagnosis. He said he would learn to cope with vision in only one eye.

While this could be dismissed as a rare, isolated incident, as a retinal specialist, I see patients referred for complex macular issues. I’ve encountered two other similar cases of day-one "patch-off" vision loss after cataract surgery under subtenon anesthesia. I even had a similar case myself, although thankfully, that patient retained good central vision (6/6) despite some retinal thinning and paracentral field defects.

Something needs to change.

The motivation to transition to topical anaesthesia for cataract surgery

The editorial I mentioned suggested a possible link between subtenon anesthesia and this devastating complication. While subtenon anesthesia is necessary for some procedures like vitrectomies, cataract surgery can be safely performed using topical anesthesia. Leading cataract surgeons like David Chang and Uday Devgan routinely perform high-volume surgeries this way.

Topical anesthesia also offers several other advantages:

• Reduced fall risk: Covering one eye after subtenon anesthesia increases the risk of falls, especially in elderly patients. Topical anesthesia allows for immediate vision recovery, minimising this risk.
• Faster recovery: Recovery is generally quicker with topical anesthesia.
• Reduced anxiety: Many patients find the subtenon injection – a needle inserted into the orbit behind the eye – anxiety-provoking.

‍

So why not all eye surgeons do their cataract surgery under topical anaesthesia

Simply put, it's more technically demanding. Surgeons must operate quickly and gently, minimising trauma to the eye and managing any sudden eye movements. A high level of surgical skill is essential before making this transition.

In my opinion, surgeons should meet these criteria before switching to topical anesthesia:

• Operating time of 12 minutes or less: Patients struggle to maintain focus for longer periods under topical anesthesia.
• Posterior capsule complication rate of less than 1%: Ideally, it should be much lower. For doctors in training, a posterior capsule complication rate of 1-2 cases in the last 100 cases is acceptable as long as one is operating under consultant supervision.
• Gentle surgical technique: Minimising tissue trauma is crucial.

‍

My Topical Anesthesia Protocol

"Everything should be made as simple as possible, but no simpler" - Albert Einstein

When I first explored topical anesthesia, I encountered various techniques. Some used lignocaine gel, others combined it with taping, and some even applied gel outside the eyelids. Some surgeons insisted on specific speculums or used intracameral lidocaine. None of these methods gave me the results I wanted.

Then, I consulted my friend, Associate Professor James McKelvie, a high-volume cataract surgeon in Hamilton who uses a simple topical anesthesia technique. He generously shared his knowledge, which shaped my approach.

Here’s my current protocol:

1. Dilate the eye: Follow your standard dilation protocol.
2. Administer anesthetic drops: Apply three rounds of amethocaine drops two minutes apart to the operative eye. Also, put one drop in the other eye for comfort and to prevent the patient from closing it.
3. Draping (crucial): Stand behind the patient, ask them to look up, lower the drape, adhere it to the lower lid, and then roll it towards the upper lid. This makes draping much easier as patients are more likely to keep their eyes open when looking up.
4. Use any speculum: Choose a speculum you’re comfortable with.
5. Apply viscoelastic: This coats the eye and avoid the need of using BSS to irrigate the eye. Patients under topical anaesthetic can feel the irrgation solution on the cornea.
6. Use intracameral lidocaine only if needed: This is usually only necessary for iris manipulation.
7. Communicate with the patient: Describe what they will experience, not what you are doing. Uday Devgan has an excellent script for this purpose.

‍

My Current Practice

I've been offering topical anesthesia for selected patients in private practice for some time. Due to the compelling reasons outlined above, I now offer it to all cataract patients, both in private and public settings. While some surgeons avoid topical anesthesia for public hospital patients due to higher case complexity, I've had success with both groups using this protocol.

There are some relative contraindications, such as dementia, inability to follow instructions, and deafness. However, you can always start with topical anesthesia and convert to subtenon if necessary.

About Dr Leo Sheck

Book your appointment now to see Dr Sheck

Dr Sheck is a RANZCO-qualified, internationally trained ophthalmologist. He combined his initial training in New Zealand with a two-year advanced fellowship in Moorfield Eye Hospital, London. He also holds a Doctorate in Ocular Genetics from the University of Auckland and a Master of Business Administration from the University of Cambridge. He specialises in medical retina diseases (injection therapy), cataract surgery, ocular genetics, uveitis and electrodiagnostics.